Lipid and fatty acid composition during embryo and larval development of puye Galaxias maculatus Jenyns, 1842, obtained from estuarine, freshwater and cultured populations

Abstract

Galaxias maculatus eggs and larvae obtained from broodfish captured either in an estuarine or a freshwater environment, as well as from cultured broodstock were analysed to compare their lipid and fatty acid profiles. Results showed a lower lipid content in embryos and larvae from estuarine populations than those from fresh water, denoting the influence of environmental conditions. The n-3:n-6 ratio was higher in eggs from estuarine and cultured populations, being in the range of marine fishes, whereas for eggs from freshwater fish was lower and typical of freshwater fishes. The polyunsaturated fatty acids (PUFA), particularly docosahexaenoic acid (22:6n-3) and eicosapentaenoic acid (20:5n-3), were higher in eggs and larvae of broodstock coming from culture or estuarine environments than in those from fresh water. Moreover, these fatty acids markedly increased after hatching in larvae coming from estuarine populations, suggesting the effect of the environment on fatty acid profiles to physiologically prepare the larvae to adapt to higher salinity conditions. Linoleic acid (18:2n-6) content was higher in fresh water fish and its reduction during embryo and larval development was accompanied by a significant increase of arachidonic acid (20:4n-6), which was not observed in embryos or larvae from broodstock fish from estuary or aquaculture origin. Both environment and diet of broodstock fish affected lipid and fatty acid composition of G. maculatus embryo and larvae as well as their changes during development.

Effect of salinity on the biosynthesis of n-3 long-chain polyunsaturated fatty acids in silverside Chirostoma estor

“…These changes in activity reflected changes in the expression of fatty acyl desaturase genes in freshwater and seawater phases (Zheng et al 2005). There are also several studies reporting fatty acid compositions in fish reared at different salinities (Cordier et al 2002;Kheriji et al 2003;Haliloglu et al 2004;Martinez-Alvarez et al 2005;Dantagnan et al 2007;Navarro et al 2009;Xu et al 2010;Hunt et al 2011). Results are not consistent with increased associated with both reduced (Ciordier et al 2002;Kheriji et al 2003) and increased (Xu et al 2010;Hunt et al 2011) levels of LC-PUFA including EPA and DHA.…”

Fatty acid composition and volatile compounds of caviar from farmed white sturgeon (Acipenser transmontanus)

“…The n-6 series tends to predominate in fresh water derived fish eggs while n-3 characterize fish eggs from salt water environments [43,44]. Recently, Dantagnan et al [41] reported how cultured broodstock embryos of "puyen" (Galaxias maculates), which were kept in fresh water during the entire cycle, but given diets based on fish meal and oil, showed a n-3/n-6 ratio close to embryos from estuarine fish.…”

“…The fatty composition of eggs has been studied in both wild and cultured freshwater populations [6,41,42] and it is also known to be affected by dietary and environmental factors. The n-6 series tends to predominate in fresh water derived fish eggs while n-3 characterize fish eggs from salt water environments [43,44].…”

Blood cytology of the common jollytail (Galaxias maculatus) (Jenyns, 1842) (Osmeriformes: Galaxiidae) at postlarval and adult stages

“…As a result of the high market value and commercial interest for "cristalinos" this fish has been described as a potential new species for Chilean aquaculture diversification. The School of Aquaculture of the Catholic University of Temuco, Chile, has been involved in the research and development of larval rearing and feeding techniques for the culture of G. maculatus for over ten years (Bórquez et al 1996, Dantagnan et al 2002, Barile et al 2003, Dantagnan et al 2004, Dantagnan et al 2005, Dantagnan et al 2007. The success when introducing a new species to aquaculture relies on, among other things, the detailed knowledge of the physiology of the species.…”